From owner-freebsd-current Thu Sep 21 16: 2:15 2000 Delivered-To: freebsd-current@freebsd.org Received: from mass.osd.bsdi.com (adsl-63-202-177-115.dsl.snfc21.pacbell.net [63.202.177.115]) by hub.freebsd.org (Postfix) with ESMTP id 6F74F37B423 for ; Thu, 21 Sep 2000 16:02:13 -0700 (PDT) Received: from mass.osd.bsdi.com (localhost [127.0.0.1]) by mass.osd.bsdi.com (8.9.3/8.9.3) with ESMTP id QAA62850; Thu, 21 Sep 2000 16:03:02 -0700 (PDT) (envelope-from msmith@mass.osd.bsdi.com) Message-Id: <200009212303.QAA62850@mass.osd.bsdi.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: Warner Losh Cc: current@FreeBSD.ORG Subject: Re: new idle_proc() makes my laptop very hot In-reply-to: Your message of "Thu, 21 Sep 2000 16:50:09 MDT." <200009212250.QAA62765@harmony.village.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 21 Sep 2000 16:03:02 -0700 From: Mike Smith Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > My laptop does seem to run *MUCH* warmer than before as well. It runs > hot to begin with, but with the latest kernels it runs really hot. It > used to get this hot only when I compiled -j 4. I don't have ACPI > enabled and am using UP kernel. There really needs to be a HLT in the > idle loop to keep idle machines cools. If I remember from a discussion with John Baldwin, the reason we don't do this (yet) is that HLT only wakes up when you take an interrupt, and there are cases where we can't guarantee that we'll take an interrupt in order to get us out of the HLT. > The thermal management code, iirc, works in conjunction with this by > lower the clock rate when things aren't too loaded, but that is a > fairly complex thign to wait for. It also seems to help mostly on > lightly loaded machines. HLT helps more than you'd otherwise > think...c HLT helps a lot, yes, but the thermal management code is responsible for running the system fan(s) in ACPI mode as well as throttling the CPU. In some cases, that's a real issue (eg. I'm building the world now and extremely worried about how hot this system is because I forgot to turn ACPI off first. 8) -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message